Display component, display device, and method for manufacturing same

ABSTRACT

Provided is a method for manufacturing a display device. The method includes forming a display unit including a bending area on a first surface of a mother substrate, aligning a mask in which a mask opening is defined on a second surface of the mother substrate, plasma treating the second surface of the mother substrate, removing the mask and attaching a protective film to the second surface of the mother substrate, and removing a portion of the protective film to form a film opening corresponding to the bending area. The mask opening corresponds to the bending area.

This application claims priority to Korean Patent Application No.10-2019-0053052, filed on May 7, 2019, and all the benefits accruingtherefrom under 35 U.S.C. § 119, the contents of which in its entiretyis herein incorporated by reference.

BACKGROUND 1. Field

The present disclosure herein relates to a display device.

2. Description of the Related Art

Various display devices used in multimedia devices such as televisions,mobile phones, tablet computers, navigation systems, and game consolesare being developed. These display devices include a display moduledisposed on a substrate. The substrate of the display device may beelectrically connected to a circuit substrate which provides drivingsignals.

Pads and other components for electrically connecting to the circuitboard are arranged in a non-display area of the substrate. When it isdesired to dispose a display area on the entire one surface of thedisplay device, the non-display area in which the pads and othercomponents are arranged should be minimized.

Efforts for reducing the non-display area in the display devicecontinues by bending a portion of the substrate.

SUMMARY

The present disclosure provides a display device in which a portion of asubstrate may be bent and a method for manufacturing the same.

The present disclosure also provides a display component which may beapplied to a display device in which a portion of a substrate may bebent.

An exemplary embodiment of the invention provides a method formanufacturing a display device. The method includes forming a displayunit including a bending area on a first surface of a mother substrate,aligning a mask in which a mask opening is defined on a second surfaceof the mother substrate, plasma treating the second surface of themother substrate, removing the mask and attaching a protective film tothe second surface of the mother substrate, and removing a portion ofthe protective film to form a film opening corresponding to the bendingarea. The mask opening corresponds to the bending area.

In an exemplary embodiment, the protective film may include an adhesivelayer and a protective film base, and the protective film base may beattached to the second surface of the mother substrate through theadhesive layer therebetween.

In an exemplary embodiment, the protective film base may includepolyimide.

In an exemplary embodiment, the removing of the portion of theprotective film may include irradiating the second surface of the mothersubstrate corresponding to the bending area with ultraviolet light.

In an exemplary embodiment, the plasma treating may include injectingthe mother substrate into a reactor and performing a plasma treatment ofthe mother substrate during a predetermined processing time in thereactor.

In an exemplary embodiment, the display unit may further include anon-bending area adjacent to the bending area, and the processing timemay be set such that a proportion of a silicon polymeric material on aportion of the second surface of the mother substrate corresponding tothe bending area becomes greater than a proportion of a siliconpolymeric material on another portion of the second surface of themother substrate corresponding to the non-bending area.

In an exemplary embodiment, a rate at which the mother substrate passesthrough the reactor may be 100 millimeters per second (mm/s) or more.

In an exemplary embodiment, the forming of a display unit may includeforming a plurality of display units disposed apart from each other onthe first surface of the mother substrate, and each of the plurality ofdisplay units may include the bending area.

In an exemplary embodiment of the invention, a display device includes asubstrate which includes a first surface, a second surface, a bendingarea, and a non-bending area, a display module which is disposed on thefirst surface of the substrate, and a protective film which is disposedon the second surface of the substrate and defines an openingcorresponding to the bending area. Here, a proportion of a siliconpolymeric material of the bending area is greater than a proportion of asilicon polymeric material of the non-bending area in the secondsurface.

In an exemplary embodiment, the protective film may include an adhesivelayer and a protective film base, and the protective film base may beattached to the second surface of the substrate through the adhesivelayer therebetween.

In an exemplary embodiment, the protective film base may includepolyimide.

In an exemplary embodiment, the substrate may be bent with respect to abending axis, and the non-bending area may include a first non-bendingarea and a second non-bending area.

In an exemplary embodiment, the bending area may be disposed between thefirst non-bending area and the second non-bending area.

In an exemplary embodiment, the display module may be disposed on thefirst non-bending area of the first surface of the substrate.

In an exemplary embodiment, the display device may further include a padwhich is disposed on the substrate and electrically connected to thedisplay module, and the pad may be disposed in the second non-bendingarea.

In an exemplary embodiment of the invention, a display componentincludes a mother substrate which includes a first surface and a secondsurface, a plurality of display units which is disposed on the firstsurface of the mother substrate, and a protective film which is disposedon the second surface of the mother substrate and includes a pluralityof openings. The mother substrate includes a plurality of bending areascorresponding to the plurality of display units, respectively, and theplurality of openings of the protective film correspond to the pluralityof bending areas, respectively.

In an exemplary embodiment, the protective film may include an adhesivelayer and a protective film base, and the protective film base may beattached to the second surface of the mother substrate through theadhesive layer therebetween.

In an exemplary embodiment, the protective film base may includepolyimide.

In an exemplary embodiment, the mother substrate may further includenon-bending areas which correspond to the plurality of display units,respectively, and are adjacent to the plurality of bending areas, andeach of the display units may be disposed in the correspondingnon-bending area among the non-bending areas.

In an exemplary embodiment, a proportion of a silicon polymeric materialof the bending area is greater than a proportion of a silicon polymericmaterial of the non-bending area in the second surface of the mothersubstrate.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the invention, and are incorporated in and constitute apart of this specification. The drawings illustrate exemplaryembodiments of the invention and, together with the description, serveto explain principles of the invention. In the drawings:

FIG. 1 is a perspective view of an exemplary embodiment of a displaydevice according to the invention;

FIG. 2 is a cross-sectional view an exemplary embodiment of a displaydevice according to the invention;

FIG. 3 is a plan view of an exemplary embodiment of a display unitaccording to the invention;

FIG. 4 illustrates a partial cross-sectional view of an exemplaryembodiment of a display device corresponding to one pixel and one padillustrated in FIG. 3;

FIG. 5 is a perspective view schematically illustrating an exemplaryembodiment of a portion of a display device according to the invention;

FIG. 6 is a view illustrating a mask disposed on a back surface of amother substrate;

FIGS. 7A to 7E are views illustrating a process for forming a protectivefilm;

FIGS. 8A to 8F are exemplary views showing amount variations of siliconmonomeric and polymeric materials in a plasma treated bending area;

FIG. 9 is an exemplary view showing an adhesion variation of a bendingarea according to a plasma treatment time; and

FIG. 10 is a cross-sectional view illustrating that an exemplaryembodiment of a substrate of a display device is bent according to theinvention.

DETAILED DESCRIPTION

It will be understood that when an element (or region, layer, portion,etc.) is referred to as being “on”, “connected to” or “coupled to”another element, it can be directly on, connected or coupled to theother element or layer or intervening elements may also be present.

Like numbers refer to like elements throughout. The thickness and theratio and the dimension of the element are exaggerated for effectivedescription of the technical contents.

The term “and/or” includes any and all combinations of one or more ofthe associated listed items.

The terms first and second may be used to describe various elements,however, the elements should not be limited by these terms. These termsare merely used for the purpose of discriminating one element fromanother element. For example, the first element may be designated as thesecond element, and similarly, the second element may also be designatedas the first element, without departing from the spirit or scope of theinvention. A singular form, otherwise indicated, include a plural form.

Further, the terms “under”, “below”, “on”, “above”, and the like, may beused herein for ease of description to describe one element or feature'srelationship to another element(s) or feature(s) as illustrated in thefigures. It will be understood that the terms are relative concept, anddescribed on the basis of the direction illustrated in the figures.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning that is generally understood bya person skilled in the art. It will be further understood that theterms such as defined terms in commonly the dictionary should beconsidered to have the same meaning as the contextual meaning of therelated art, and, unless understood abnormally or excessively formalmeaning, should be expressly defined herein.

In the description, it should be understood that the term “comprise” or“have” intends to mean that there may be specified features, numerals,steps, operations, elements, parts, or combinations thereof, notexcluding the possibility of the presence or addition of the specifiedfeatures, numerals, steps, operations, elements, parts, or combinationsthereof.

Hereinafter, exemplary embodiments of the invention will be describedwith reference to the drawings.

FIG. 1 is a perspective view of an exemplary embodiment of a displaydevice DD according to the invention.

As illustrated in FIG. 1, a display surface IS on which an image IM isdisplayed is parallel to a plane defined by a first directional axis DR1and a second directional axis DR2. A normal direction of the displaysurface IS, that is, a thickness direction of the display device DD, isindicated by a third directional axis DR3. A front surface (or uppersurface) and a back surface (or lower surface) of each of members of thedisplay device DD are distinguished by the third directional axis DR3.However, the directions indicated by the first to third directional axesDR1, DR2, and DR3 are relative concepts, and may be converted intodifferent directions. Hereinafter, first to third directions refer tothe same reference numerals in the directions indicated by the first tothird directional axes DR1, DR2, and DR3, respectively.

Exemplary embodiments of the display device DD according to theinvention may be large-sized electronic devices such as a television anda monitor, and also be medium and small-sized electronic devices such asa mobile phone, a tablet, a car navigation system, a game console, and asmart watch.

As illustrated in FIG. 1, the display device DD includes a display areaDA for displaying the image IM and a non-display area NDA adjacent tothe display area DA. The non-display area NDA is an area in which animage is not displayed. As an example, the display area DA may have arectangular shape. The non-display area NDA may surround the displayarea DA. However, the invention is not limited thereto. In anotherexemplary embodiment, the shape of the display area DA and the shape ofthe non-display area NDA may be relatively designed.

FIG. 2 is a cross-sectional view of an exemplary embodiment of a displaydevice DD according to the invention. FIG. 2 illustrates a cross-sectiondefined by the second directional axis DR2 and the third directionalaxis DR3.

As illustrated in FIG. 2, the display device DD includes a substrate SUBand a display module DM. The display device DD according to an exemplaryembodiment of the invention further includes a protective film FLMdisposed on a lower surface of the substrate SUB. Although notseparately illustrated, the display device DD may further include anantireflective member and/or a window member disposed on an uppersurface of the display module DM. In another exemplary embodiment, thedisplay device DD may further include a touch sensing unit for sensing auser's touch input and between the upper surface of the display moduleDM and the window member (not illustrated).

The display module DM may be a luminescence display panel, and is notparticularly limited thereto. For example, the display module DM may bean organic luminescence display panel or a quantum dot luminescencedisplay panel. In the organic luminescence display panel, an emissionlayer includes an organic luminescence material. In the quantum dotluminescence display panel, an emission layer includes a quantum dotand/or a quantum rod. Hereinafter, the display module DM will bedescribed as an organic luminescence display panel.

The substrate SUB may include at least one plastic film. The substrateSUB may be a flexible substrate, and may include a plastic substrate, aglass substrate, a metal substrate, or an organic/inorganic compositematerial substrate. The display area DA and the non-display area NDAdescribed with reference to FIG. 1 may be equally defined on thesubstrate SUB.

In addition, the substrate SUB may include at least one non-bending areaand a bending area BA. In an exemplary embodiment, the substrate SUBincludes two non-bending areas, that is, a first non-bending area NBA1and a second non-bending area NBA2, but the invention is not limitedthereto.

The first non-bending area NBA1 and the second non-bending area NBA2 aredisposed apart from each other along the second directional axis DR2,and the bending area BA is disposed between the first non-bending areaNBA1 and the second non-bending area NBA2.

The display module DM includes a circuit element layer CL, a lightemitting element OLED, and a thin film encapsulation layer TFE which aredisposed on the substrate SUB. Although not separately illustrated, thedisplay module DM may further include functional layers such as anantireflective layer and a refractive index control layer.

The circuit element layer CL includes at least one intermediateinsulating layer and a circuit element. The intermediate insulatinglayer includes at least one intermediate inorganic film and at least oneintermediate organic film. The circuit element includes signal lines,driving circuits of pixels, etc. A detailed description thereof will bedescribed later.

The light emitting element OLED includes at least organic luminescencediodes. The light emitting element OLED may further include an organicfilm such as a pixel defining film.

The thin film encapsulation layer TFE seals the light emitting elementOLED. The thin film encapsulation layer TFE includes at least oneinorganic film (hereinafter, referred to as encapsulation inorganicfilm). The thin film encapsulation layer TFE may further include atleast one organic film (hereinafter, referred to as encapsulationorganic film). The encapsulation inorganic film protects the lightemitting element OLED from moisture/oxygen, and the encapsulationorganic film protects the light emitting element OLED from foreignsubstances such as dust particles. The encapsulation inorganic film mayinclude a silicon nitride layer, a silicon oxynitride layer and asilicon oxide layer, a titanium oxide layer, or an aluminum oxide layer.The encapsulation organic film may include an acrylic-based organiclayer, but the present invention is not limited to.

The protective film FLM is attached to the lower surface of thesubstrate SUB. The protective film FLM serves to prevent foreignsubstances such as air and water from permeating through the lightemitting element OLED from the outside and protect the same fromexternal impact. The protective film FLM defines a film opening FLM-OPcorresponding to the bending area BA. In an exemplary embodiment, thefilm opening FLM-OP may have a length substantially equal to the bendingarea BA in the second directional axis DR2, but the invention is notlimited thereto. That is, the length of the film opening FLM-OP in thesecond directional axis DR2 may be longer or shorter than the bendingarea BA. The protective film FLM and the film opening FLM-OP will bedescribed later in detail.

FIG. 3 is a plan view of an exemplary embodiment of a display unitaccording to the invention. In addition, for ease of description, inFIG. 3 some components of the display unit are omitted.

As illustrated in FIG. 3, the display device DD includes a display areaDA and a non-display area NDA on the same plane. In the exemplaryembodiment, the non-display area NDA may be defined along a rim of thedisplay area DA at the outskirts of the display area DA.

The display device DD may include a scan driving circuit SDC, aplurality of signal lines SGL (hereinafter referred to as signal lines),a plurality of data pads PD, and a plurality of pixels PX (hereinafterreferred to as pixels) disposed on a substrate SUB. The pixels PX aredisposed in the display area DA. Each of the pixels PX includes anorganic luminescence diode and a pixel driving circuit connectedthereto.

The scan driving circuit SDC may include a scan driving circuit. Thescan driving circuit generates a plurality of scan signals (hereinafterreferred to as scan signals) and sequentially outputs the scan signalsto a plurality of scan lines SL (hereinafter referred to as scan lines)which will be described later. The scan driving circuit may furtheroutput another control signal to a driving circuit of pixels PX.

The scan driving circuit SDC may include a plurality of thin filmtransistors formed through the same process as the driving circuit ofpixels PX, for example, a low temperature polycrystalline silicon(“LTPS”) process or a low temperature polycrystalline oxide (“LTPO”)process.

The signal lines SGL include scan lines SL, data lines DL, a powersupply line PL, and a control signal line CSL. The scan lines SL areconnected to the corresponding pixels PX, respectively, and the datalines DL are connected to the corresponding pixels PX, respectively. Thepower supply line PL is connected to the pixels PX. The control signalline CSL may provide control signals to the scan driving circuit SDC.

The signal lines SGL overlap the display area DA and the non-displayarea NDA. The signal lines SGL may include a pad portion and a lineportion. The line portion overlaps the display area DA and thenon-display area DP. The pad portion is connected to the end of the lineportion. The pad portion is disposed in the non-display area NDA andoverlaps the corresponding data pads PD. An area in which the data padsPD are disposed in the non-display area NDA may be defined as a pad areaPDA.

The line portion connected to the pixel PX substantially constitutesmost of the signal lines SGL. The line portion is connected totransistors (not illustrated) of the pixel PX. The line portion may havea single layer/multilayer structure, and the line portion may be asingle body or may include two or more parts. The two or more parts maybe disposed on different layers and may be connected to each otherthrough a contact hole which passes through an insulating layer disposedbetween the two or more parts.

The substrate SUB may include at least one non-bending area and bendingarea BA. In the exemplary embodiment illustrated in FIG. 3, thesubstrate SUB includes two non-bending areas, that is, a firstnon-bending area NBA1 and a second non-bending area NBA2, but theinvention is not limited thereto.

The first non-bending area NBA1 and the second non-bending area NBA2 aredisposed apart from each other in the second directional axis DR2, andthe bending area BA is disposed between the first non-bending area NBA1and the second non-bending area NBA2.

The first non-bending area NBA1 includes the display area DA and thesecond non-bending area NBA2 includes the pad area PDA. In an exemplaryembodiment, a length of the first non-bending area NBA1 along the seconddirectional axis DR2 is longer than a length of the display area DA inthe same direction, and a length of the second non-bending area NBA2along the second directional axis DR2 is longer than a length of the padarea PDA in the same direction. However, the invention is not limitedthereto.

FIG. 3 additionally illustrates a printed circuit board FCB electricallyconnected to the display device DD. The printed circuit board FCB may bea rigid circuit board or a flexible circuit board. The printed circuitboard FCB may be directly connected to the display device DD or may beconnected to the display device DD through another circuit board.

A panel drive circuit PDC for controlling operation of the displaydevice DD may be disposed on the printed circuit board FCB. Although notillustrated in the drawing, a plurality of passive elements may befurther disposed on the printed circuit board FCB. The panel drivecircuit PDC may be mounted on the printed circuit board FCB in a form ofan integrated chip. The printed circuit board FCB may include board padsF-PD electrically connected to the data pads PD of the display deviceDD. The board pads F-PD may be disposed in a board pad area F-PDA. Theprinted circuit board FCB further includes signal lines connecting theboard pads F-PD and the panel drive circuit PDC.

FIG. 4 illustrates a partial cross-sectional view of an exemplaryembodiment of a display device corresponding to one pixel and one padillustrated in FIG. 3.

Referring to FIGS. 3 and 4, the substrate SUB may be an insulatingsubstrate. For example, the substrate SUB may include a plasticsubstrate or a glass substrate. An auxiliary layer BL is disposed on thesubstrate SUB and covers the entire surface of the substrate SUB. Theauxiliary layer BL includes an inorganic material. The auxiliary layerBL may include a barrier layer and/or a buffer layer. Accordingly, theauxiliary layer BL may prevent oxygen or moisture entering through thesubstrate SUB from permeating the pixel PX. In addition, the auxiliarylayer BL improves a binding force between the substrate SUB andconductive patterns or semiconductor patterns.

The pixel PX may be disposed in the display area DA. In the exemplaryembodiment, it is exemplarily illustrated and described that the pixelPX includes one transistor TR and light emitting element OLED, but theinvention is not limited thereto. In another exemplary embodiment, forexample, one pixel PX may include two or more transistors. Each of firstto fourth insulating layers 10, 20, 30, and 40 may include an organicmaterial and/or an inorganic material, and may have a single layer or alaminated structure.

The transistor TR is disposed on the substrate SUB, and may include acontrol electrode CE, an input electrode IE, an output electrode OE, anda semiconductor pattern SP. The control electrode CE is disposed apartfrom the semiconductor pattern SP with the first insulating layer 10therebetween, and connected to one electrode of a capacitor. Each of theinput electrode IE and output electrode OE is disposed on the secondinsulating layer 20, and connected to the semiconductor pattern SP bypassing through the first insulating layer 10 and second insulatinglayer 20. The input electrode IE is connected to another electrode ofthe capacitor, and the output electrode OE is connected to the lightemitting element OLED.

The light emitting element OLED includes a first electrode E1, anemission layer EL, and a second electrode E2. The first electrode E1 isdisposed on the third insulating layer 30, and connected to thetransistor TR by passing through the third insulating layer 30. Theemission layer EL covers the first electrode E1 exposed by the fourthinsulating layer 40. The emission layer EL may include a luminescencematerial which generates light corresponding to a potential difference.For example, the emission layer EL may include an organic luminescencematerial or a quantum dot.

The second electrode E2 is disposed on the emission layer EL. The secondelectrode E2 may be disposed on the entire surface of the display areaDA. The second electrode E2 may extend from the display area DA to thenon-display area NDA, and be connected to a connection pattern. Theconnection pattern may correspond to a power supply terminal.

The light emitting element OLED, controlled by the transistor TR,generates and emits light corresponding to a potential differencebetween a data signal supplied to the first electrode E1 and a powersupply voltage (e.g., a ground voltage) supplied to the second electrodeE2.

A first conductive pattern CP1 connects the data line DL and the datapad PD. The first conductive patterns CP1 may include a plurality ofline patterns each extending along the second direction DR2 and disposedapart from each other along the first direction DR1.

In the exemplary embodiment, the first conductive pattern CP1 may bedisposed in a different layer from the data lines DL. For example, thefirst conductive pattern CP1 may be disposed in the same layer as thecontrol electrode CE, that is, scan line SL. At this time, a data lineconnection end DL-P extending from the data lines DL may be connected tothe first conductive pattern CP1 through a contact hole CH which isdefined in the second insulating layer 20. The first conductive patternCP1 is disposed between the first insulating layer 10 and secondinsulating layer 20.

However, the exemplary embodiment above is exemplarily illustrated. Inanother exemplary embodiment, the first conductive pattern CP1 may bedisposed in the same layer as the data lines DL. For example, the firstconductive pattern CP1 may be integrally formed with the data lines DLand provided as a portion of the data lines DL, or may be connected toeach of the data lines DL through a separate bridge pattern, etc. Thefirst conductive pattern CP1 according to an exemplary embodiment of theinvention may be provided in various forms as long as it may beconnected to the data lines DL, and the invention is not limited to anyone exemplary embodiment.

The encapsulation layer TFE is disposed on the fourth insulating layer40 to seal the light emitting element OLED. The encapsulation layer TFEmay include a first inorganic film IOL1, an organic film OL, and asecond inorganic film IOL2 which are sequentially laminated along thethird direction DR3. However, the exemplary embodiment above isexemplarily illustrated. In another exemplary embodiment, theencapsulation layer TFE may further include an inorganic film and anorganic film, and at least one of the first inorganic film IOL1, theorganic film OL, and the second inorganic film IOL2 may be omitted. Inan exemplary embodiment, the organic film OL may extend to an area inwhich the scan driving circuit SDC is disposed.

The data pad PD is connected to the first conductive pattern CP1. In anexemplary embodiment, the data pad PD may be a data pad for transferringa data signal provided from the printed circuit board FCB to the dataline DL.

In an exemplary embodiment, the data pad PD may be disposed in adifferent layer from the first conductive pattern CP1. For example, thedata pad PD may be disposed on the second insulating layer 20, andconnected to the first conductive pattern CP1 by passing through thesecond insulating layer 20. However, the exemplary embodiment above isexemplarily illustrated. In another exemplary embodiment, the data padPD may be disposed in the same layer as the first conductive patternCP1, or may be integrally formed with the first conductive pattern CP1.

The display device DD further includes a protective film FLM disposed ona lower surface of the substrate SUB. The protective film FLM includesan adhesive layer PSA and a protective film base FBS. The protectivefilm base FBS may be attached to a lower surface of the substrate SUB bythe adhesive layer PSA therebetween.

The protective film FLM defines a film opening FLM-OP corresponding tothe bending area BA illustrated in FIG. 3. In an exemplary embodiment,the film opening FLM-OP may have a length substantially equal to thebending area BA along the second directional axis DR2, but the inventionis not limited thereto.

FIG. 5 is a perspective view schematically illustrating an exemplaryembodiment of a portion of a display device according to the invention.

Referring to FIG. 5, a substrate SUB of the display device DD may bebent with respect to a bending axis BX. The substrate SUB may includevarious materials having flexible or bendable characteristics, such aspolyethersulphone (“PES”), polyacrylate (“PAR”), polyetherimide (“PEI”),polyethylene naphthalate (“PEN”), polyethylene terephthalate (“PET”),polyphenylene sulfide (“PPS”), polyallylate, polyimide (“PI”),polycarbonate (“PC”), or a polymer resin (e.g., cellulose acetatepropionate (“CAP”)).

A display module DM may be disposed on a first non-bending area NBA1 ofthe substrate SUB.

FIG. 6 and FIGS. 7A to 7E are views illustrating a process for forming aprotective film.

FIG. 6 is a view illustrating a mask disposed on a back surface of amother substrate.

Referring to FIG. 6, the same producing process is applied to each of aplurality of display units DU set on the mother substrate MS to form thedisplay module DM illustrated in FIG. 2. After the producing process iscompleted, the mother substrate MS is cut to separate the display unitsDU. The cut display unit DU may become the display device DD illustratedin FIG. 2.

In the mother substrate MS illustrated in FIG. 6, the display module DMis formed for each of the plurality of display units DU, and aprotective film FLM is not attached.

As illustrated in FIGS. 6 and 7A, a mask MSK, in which a plurality ofmask openings M-OP is defined, is aligned to the mother substrate MS.The mask opening M-OP may correspond to the bending area BA illustratedin FIGS. 2 and 3. The mother substrate MS, on which the mask MSK isaligned, is disposed in a plasma reactor, and then a plasma treatment isperformed thereon.

A proportion of a polydimethylsiloxane (“PDMS”) polymer on a surface ofthe mother substrate MS is changed by the plasma treatment.

Referring to FIG. 7B, the mask MSK is removed. The proportion of thePDMS polymer in the plasma-treated bending area BA becomes greater thanthe proportion of the PDMS polymer in a first non-bending area NBA1 anda second non-bending area NBA2 overlapping the mask MSK illustrated inFIG. 7A.

A protective film base FBS, on which an adhesive layer PSA is laminated,is attached onto a lower surface of the plasma treated mother substrateMS. In an exemplary embodiment, the protective film base FBS may includevarious materials having flexible or bendable characteristics, forexample, polyimide (PI).

Referring to FIG. 7C, the bending area BA of the protective film baseFBS is irradiated with a laser beam by using laser equipment LZR. Thelaser equipment LZR may be ultraviolet pico-second laser equipment. Afirst end of the bending area BA adjacent to the first non-bending areaNBA1 of the protective film base FBS is cut by an ultraviolet light La.In addition, a second end of the bending area BA adjacent to the secondnon-bending area NBA2 of the protective film base FBS is cut by anultraviolet light Lb.

Referring to FIG. 7D, a film opening FLM-OP may be formed when the cutportion of the protective film base FBS is removed. The film openingFLM-OP corresponds to the bending area BA. In the bending area BA of themother substrate MS in FIG. 7A above, the proportion of the PDMS polymeris increased by the plasma treatment, and accordingly, adhesion betweenthe bending area BA of the mother substrate MS and the adhesive layerPSA is weakened. Therefore, it is easy to remove the cut portion of theprotective film base FBS to define the film opening FLM-OP.

Referring to FIG. 7E, an upper protective film UFLM is attached to anupper portion of the mother substrate MS. Although not illustrated inthe drawing, the upper protective film UFLM may include an adhesivelayer.

In an exemplary embodiment, it is described that the protective film FLMis attached to the lower portion of the mother substrate MS, and thenthe upper protective film UFLM is attached, but the invention is notlimited thereto. In another exemplary embodiment, the upper protectivefilm UFLM may be first attached to the upper portion of the mothersubstrate MS, and then the protective film FLM may be attached to thelower portion of the mother substrate MS.

FIGS. 8A to 8F are exemplary views showing amount variations of siliconmonomeric and polymeric materials in a plasma treated bending area.

As shown in FIGS. 8A to 8C, after the plasma treatment, the amount ofsilicon monomeric materials (e.g., Si, SiCH₃, and SiC₃H₉) of the plasmatreated bending area BA is reduced as compared with the amount of thesilicon monomeric materials in the non-plasma treated non-bending areasNBA1 and NBA2 (See “Plasma-skip” in the figure).

In contrast, as shown in FIGS. 8D to 8F, after the plasma treatment, theamount of silicon polymeric materials (e.g., Si₂C₅H₁₅O, SiC₅H₁₅O₃, andSi₃C₇H₂O₂) of the plasma treated bending area BA becomes greater theamount of the silicon polymeric materials in the non-plasma treatednon-bending area NBA (See “Plasma-skip” in the figure). Particularly, aplasma treatment time for the bending area BA is controlled, whereby aproportion of a polydimethylsiloxane (PDMS) polymeric material isincreased and the adhesion may be weakened.

FIG. 9 is an exemplary view showing an adhesion variation of a bendingarea according to a plasma treatment time.

Referring to FIGS. 7A and 9, the mother substrate MS, on which a maskMSK is aligned, is disposed in a plasma reactor, and then the plasmatreatment is performed while moving in the plasma reactor. The plasmatreatment time for the mother substrate MS is inversely proportional tothe moving speed of the mother substrate MS in the reactor. That is, asthe moving speed of the mother substrate MS increases, the plasmatreatment time decreases.

In the exemplary embodiment shown in FIG. 9, it could be confirmed that,compared to when the plasma treatment on the mother substrate MS is notperformed (“Skip” in the figure), as the plasma treatment speed, thatis, the moving speed of the mother substrate MS, increases, the adhesionin the bending area BA of the mother substrate MS decreases. Forexample, when the moving speed is 200 millimeters per second (mm/s), theadhesion decreases more than when the moving speed is 100 mm/s.Furthermore, when the moving speed is 300 mm/s, the adhesion decreasesmore than when the moving speed is 200 mm/s. Although not shown in thedrawing, when the moving speed of the mother substrate MS is slower than100 mm/s, an effect of decreasing the adhesion in the bending area BA ofthe mother substrate MS is not large, and therefore, the moving speed ofthe mother substrate MS is preferably 100 mm/s or more.

FIG. 10 is a cross-sectional view illustrating that an exemplaryembodiment of a substrate of a display device is bent according to theinvention.

As illustrated in FIG. 10, the substrate SUB of the display device DDmay be bent in a bending area BA.

A protective film base FBS of a protective film FLM serves to protect alower surface of the substrate SUB, and accordingly may have rigidityitself, which makes flexibility of the protective film base FBS low.Accordingly, in a case that the protective film base FBS covers thebending area BA, when the substrate SUB is bent, peeling may occurbetween the protective film base FBS and the substrate SUB. In contrast,an exemplary embodiment of the protective film FLM of the display deviceDD according to the invention has an opening FLM-OP corresponding to thebending area BA to effectively prevent such peeling from occurring.

Furthermore, when a bending radius of the substrate SUB is small, theprotective film base FBS may be composed of polyimide having flexible orbendable characteristics. According to an exemplary embodiment, peelingof the protective film base FBS composed of polyimide may be facilitatedby plasma treating of the bending area BA of the mother substrate MS.

A display device having such a structure above may include a protectivefilm under a substrate to protect a lower surface of the substrate.Furthermore, the protective film may define an opening corresponding toa bending area of the substrate to facilitate bending of the substrate.

Although the invention has been described with reference to preferredexemplary embodiments of the invention, it will be understood by thoseskilled in the art that various changes in form and details may be madetherein without departing from the spirit and scope of the invention.

Accordingly, the technical scope of the invention is not intended to belimited to the contents set forth in the detailed description of thespecification, but is intended to be defined by the appended claims.

What is claimed is:
 1. A method for manufacturing a display device, the method comprising: forming a display unit comprising a bending area and a non-bending area on a first surface of a mother substrate; aligning a mask in which a mask opening is defined on a second surface of the mother substrate; plasma treating the second surface of the mother substrate; removing the mask and attaching a protective film to the second surface of the mother substrate; and removing a portion of the protective film to define a film opening therethrough corresponding to the bending area, wherein the mask opening defines the film opening and corresponds to the bending area, wherein the second surface of the mother substrate comprises polymer resin, and by the plasma treating, a first proportion of a polymer in the bending area is greater than in a second proportion of the polymer the non-bending area.
 2. The method of claim 1, wherein the protective film comprises an adhesive layer and a protective film base, and the protective film base is attached to the second surface of the mother substrate through the adhesive layer therebetween.
 3. The method of claim 2, wherein the protective film base comprises polyimide.
 4. The method of claim 1, wherein the removing of the portion of the protective film comprises irradiating the second surface of the mother substrate corresponding to the bending area with ultraviolet light.
 5. The method of claim 1, wherein the plasma treating comprises: injecting the mother substrate into a reactor; and performing a plasma treatment of the mother substrate during a predetermined processing time in the reactor.
 6. The method of claim 5, wherein the display unit further comprises a non-bending area adjacent to the bending area, and the processing time is set such that a proportion of a silicon polymeric material on a portion of the second surface of the mother substrate corresponding to the bending area becomes greater than a proportion of a silicon polymeric material on another portion of the second surface of the mother substrate corresponding to the non-bending area.
 7. The method of claim 6, wherein a rate at which the mother substrate passes through the reactor is 100 millimeters per second (mm/s) or more.
 8. The method of claim 1, wherein the forming of the display unit comprises forming a plurality of display units disposed apart from each other on the first surface of the mother substrate, and each of the plurality of display units comprises the bending area. 